Climate science has focused on reducing emissions of atmospheric CH from paddy soils, as CH has stronger infrared absorption characteristics than CO. Like cable bacteria, artificial electron snorkels (made of solid graphite rods) have been proposed in this study to provide potential remote electron acceptors for soil anaerobic metabolism to compete with methanogenic processes. A systematic investigation was conducted on the modulation of the CH emission dynamics by electron snorkels at different densities, as well as the associated metabolism of C/N/Fe in paddy soil. During 124 days of operation, the electron snorkels suppressed CH emissions by 7–31% over ten sampling periods, and the high-density setting exhibited stronger performance. The electron snorkels accelerated the early mineralization of soil organic matter, increasing the content of dissolved organic matter by 20–236%. These organics were utilized by microorganisms, where O, NO, and Fe acted as electron acceptors, enhancing soil alternative respiration and producing CO. Metagenomic and 16S rRNA gene sequencing revealed that microbial abundance and diversity were increased by 4–71% in the soil bottom layer (7 cm–8 cm depth) driven by electron snorkels. Moreover, electron snorkels potentially prevented CH escape by either improving soil permeability or electrically stimulating the abundance of methanotrophs (e.g., ). The ratio of methanogenic to methane-oxidizing gene abundances was reduced by 22–66% under the electron snorkels. Our results indicate that the applied electron snorkels have significant potential in enriching the soil microbial community involved in methane cycling to mitigate CH emissions from paddy fields.

中文翻译：

---

人工电子通气管减少水稻土中CH4排放：电子传递途径和微生物群落生态的调节


气候科学的重点是减少稻田土壤中甲烷的排放，因为甲烷比二氧化碳具有更强的红外吸收特性。与电缆细菌一样，本研究提出了人造电子通气管（由固体石墨棒制成），以提供潜在的远程电子受体土壤厌氧代谢与产甲烷过程竞争。对不同密度电子通气管对 CH 排放动态的调节以及稻田土壤中 C/N/Fe 的相关代谢进行了系统研究。在124天的运行过程中，电子通气管在10个采样周期内将CH排放量抑制了7-31%，并且高密度设置表现出更强的性能。电子通气管加速了土壤有机质的早期矿化，使溶解有机质的含量增加了20-236%。这些有机物被微生物利用，其中O、NO和Fe作为电子受体，增强土壤替代呼吸并产生CO。宏基因组和16S rRNA基因测序显示，土壤底部的微生物丰度和多样性增加了4-71%由电子通气管驱动的层（7 cm–8 cm 深）。此外，电子通气管可能通过改善土壤渗透性或电刺激甲烷氧化菌的丰度来阻止甲烷逃逸（例如）。在电子通气管下，产甲烷基因与甲烷氧化基因丰度的比率降低了 22-66%。我们的结果表明，所应用的电子通气管在丰富参与甲烷循环的土壤微生物群落以减少稻田的甲烷排放方面具有巨大潜力。